English

Exploring the stellar streams and satellites around the giant low surface brightness galaxy Malin 1

Astrophysics of Galaxies 2026-05-15 v2

Abstract

Context. Giant Low Surface Brightness galaxies, such as Malin 1, host extended discs exceeding 100 kpc. Their formation and evolution remain debated, with interactions with satellite galaxies and accretion streams proposed as key contributors. Malin 1 hosts satellites and exhibits two giant stellar streams, likely the result of past interactions. Aims. We investigate the orbital dynamics of Malin 1's satellites and their possible connections with observed stellar streams, testing their nature with different formation scenarios. Methods. We constructed gravitational potentials using optical and HI data, including stellar, gaseous, and dark matter components, and explored a wide parameter space while testing NFW and ISO halo profiles. Results. Some scenarios produced bound solutions. The ISO halo model (MVirial2.6×1012 MM_{\text{Virial}} \approx 2.6 \times 10^{12}~M_{\odot}) favours bound satellite orbits more than the NFW model (MVirial1.4×1012 MM_{\text{Virial}} \approx 1.4 \times 10^{12}~M_{\odot}). Giant stellar streams could be substructures of some satellite galaxies along their leading and trailing trajectories. The most distant Malin 1 satellite could have reached pericenter 1.6\sim 1.6 Gyr ago, while closer companions interacted as early as 100\sim 100 Myr ago. At the same time, one close companion displays both leading and trailing arms in radial and polar orbits. Furthermore, we also identify some unbound solutions linking satellites with streams. Conclusions. Satellites and stream alignment indicate that past interactions shaped Malin 1's morphology. Our modelling constrains progenitors and orbital histories, providing insights into the dynamical evolution of gLSBGs. Findings are consistent with recent studies using Malin 1 kinematic data.

Keywords

Cite

@article{arxiv.2605.11419,
  title  = {Exploring the stellar streams and satellites around the giant low surface brightness galaxy Malin 1},
  author = {Roy O. E. Bustos-Espinoza and Matias Blaña and Gaspar Galaz and Marcelo D. Mora and Junais and Mousumi Das and Sudhanshu Barway and Ankit Kumar and Evelyn J. Johnston and Thomas Puzia},
  journal= {arXiv preprint arXiv:2605.11419},
  year   = {2026}
}

Comments

20 pages, 8 figures. Accepted for publication in Astronomy & Astrophysics. arXiv admin note: text overlap with arXiv:2502.11041